using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

        Person p = new Person();

        // Parameterized Constructor

        Employee e = new Employee("Ankit", "Patel");

        Console.WriteLine(Environment.NewLine);

        Console.WriteLine(String.Format("FirstName : {0} , LastName : {1}", e.FirstName , e.LastName));

        Console.WriteLine(Environment.NewLine);

        Order firstOrder = new Order(1, "FirstOrder");

        // Try using new Order();

        Order secondOrder = firstOrder;

        secondOrder.OrderName = "SecondOrder";

        Console.WriteLine(String.Format("OrderID : {0} , OrderName : {1}", firstOrder.OrderID , firstOrder.OrderName));

        Console.WriteLine(String.Format("OrderID : {0} , OrderName : {1}", secondOrder.OrderID , secondOrder.OrderName));

        // Copy Example

        Order o = new Order(1, "FirstOrder");

        Console.WriteLine("Before Copy");

        Console.WriteLine(String.Format("OrderID : {0} , OrderName : {1}", o.OrderID , o.OrderName));

        Console.WriteLine("Performed Copy");

        Order neworder = new Order(o);

        Console.WriteLine(String.Format("OrderID : {0} , OrderName : {1}", neworder.OrderID , neworder.OrderName));

        neworder.OrderName ="NewOrderName";

        Console.WriteLine(String.Format("OrderID : {0} , OrderName : {1}", o.OrderID , o.OrderName));

        Console.WriteLine(String.Format("OrderID : {0} , OrderName : {1}", neworder.OrderID , neworder.OrderName));

        Console.WriteLine(Environment.NewLine);

        Voter v18 = new Voter();

        Voter v24 = new Voter(24);

        Console.WriteLine((String.Format("Voter 18 : {0} and Voter 24 : {1}", v18.Age, v24.Age)));

    }

    // Default or /Parameter less constructor.

    public class Person {

        public string firstname;

        public string lastname;

    }

    // Parameterized Constructor 

    public class Employee {

        public string FirstName;

        public string LastName;

        public  Employee (string fname, string lname)

        {

            FirstName = fname;

            LastName = lname;

        }

    }

    public class Order{

    public int OrderID;

        public string OrderName;

        public Order() {}

        public Order(Order o) {

            OrderID = o.OrderID;

            OrderName = o.OrderName;

        }

        public Order(int OID, string OName)

        {

            OrderID = OID;

            OrderName = OName;

        }

    }

    public class Voter {

    public int Age;

        public Voter() {} //: this(18) {}

        public Voter(int age)

        {

        Age = age;  

        }

    }

}